From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 29 Jun 2020 03:26:17 -0400
Subject: [PATCH] Support old UUID format for NBT

We have stored UUID in plenty of places that did not get DFU'd

So just look for old format and load it if it exists.

diff --git a/src/main/java/net/minecraft/nbt/CompoundTag.java b/src/main/java/net/minecraft/nbt/CompoundTag.java
index be2bd47a509a03e78c380cf749cd476f332ab03d..210f81e380cb38c2d5d69849e593d2fdb54e8856 100644
--- a/src/main/java/net/minecraft/nbt/CompoundTag.java
+++ b/src/main/java/net/minecraft/nbt/CompoundTag.java
@@ -182,6 +182,12 @@ public class CompoundTag implements Tag {
     }
 
     public void putUUID(String key, UUID value) {
+        // Paper start - support old format
+        if (this.contains(key + "Most", 99) && this.contains(key + "Least", 99)) {
+            this.tags.remove(key + "Most");
+            this.tags.remove(key + "Least");
+        }
+        // Paper end
         this.tags.put(key, NbtUtils.createUUID(value));
     }
 
@@ -190,10 +196,20 @@ public class CompoundTag implements Tag {
      * You must use {@link #hasUUID(String)} before or else it <b>will</b> throw an NPE.
      */
     public UUID getUUID(String key) {
+        // Paper start - support old format
+        if (!contains(key, 11) && this.contains(key + "Most", 99) && this.contains(key + "Least", 99)) {
+            return new UUID(this.getLong(key + "Most"), this.getLong(key + "Least"));
+        }
+        // Paper end
         return NbtUtils.loadUUID(this.get(key));
     }
 
     public boolean hasUUID(String key) {
+        // Paper start - support old format
+        if (this.contains(key + "Most", 99) && this.contains(key + "Least", 99)) {
+            return true;
+        }
+        // Paper end
         Tag tag = this.get(key);
         return tag != null && tag.getType() == IntArrayTag.TYPE && ((IntArrayTag)tag).getAsIntArray().length == 4;
     }
diff --git a/src/main/java/net/minecraft/nbt/NbtUtils.java b/src/main/java/net/minecraft/nbt/NbtUtils.java
index 994bfb175446a7d2e697ff8faef36a348ed1accd..7b48db30a155006a74688809155d779b88e48092 100644
--- a/src/main/java/net/minecraft/nbt/NbtUtils.java
+++ b/src/main/java/net/minecraft/nbt/NbtUtils.java
@@ -75,6 +75,11 @@ public final class NbtUtils {
         if (compound.contains("Name", 8)) {
             string = compound.getString("Name");
         }
+        // Paper start - support string UUID's
+        if (compound.contains("Id", 8)) {
+            uUID = UUID.fromString(compound.getString("Id"));
+        }
+        // Paper end
 
         if (compound.hasUUID("Id")) {
             uUID = compound.getUUID("Id");
